start-server-and-test/src/utils.js

Starts server, waits for URL, then runs test command; when the tests end, shuts down server

const la = require('lazy-ass')
const is = require('check-more-types')
const { join } = require('path')
const { existsSync } = require('fs')
const arg = require('arg')
const debug = require('debug')('start-server-and-test')

const namedArguments = {
  '--expect': Number
}

/**
 * Returns new array of command line arguments
 * where leading and trailing " and ' are indicating
 * the beginning and end of an argument.
 */
const crossArguments = cliArguments => {
  const args = arg(namedArguments, {
    permissive: true,
    argv: cliArguments
  })
  debug('initial parsed arguments %o', args)
  // all other arguments
  const cliArgs = args._

  let concatModeChar = false
  const indicationChars = ["'", '"', '`']
  const combinedArgs = []
  for (let i = 0; i < cliArgs.length; i++) {
    let arg = cliArgs[i]
    if (
      !concatModeChar &&
      indicationChars.some(char => cliArgs[i].startsWith(char))
    ) {
      arg = arg.slice(1)
    }
    if (concatModeChar && cliArgs[i].endsWith(concatModeChar)) {
      arg = arg.slice(0, -1)
    }

    if (concatModeChar && combinedArgs.length) {
      combinedArgs[combinedArgs.length - 1] += ' ' + arg
    } else {
      combinedArgs.push(arg)
    }

    if (
      !concatModeChar &&
      indicationChars.some(char => cliArgs[i].startsWith(char))
    ) {
      concatModeChar = cliArgs[i][0]
    }
    if (concatModeChar && cliArgs[i].endsWith(concatModeChar)) {
      concatModeChar = false
    }
  }
  return combinedArgs
}

const getNamedArguments = cliArgs => {
  const args = arg(namedArguments, {
    permissive: true,
    argv: cliArgs
  })
  debug('initial parsed arguments %o', args)
  return {
    expect: args['--expect'],
    // aliases
    '--expected': '--expect'
  }
}

/**
 * Returns parsed command line arguments.
 * If start command is NPM script name defined in the package.json
 * file in the current working directory, returns 'npm run start' command.
 */
const getArguments = cliArgs => {
  la(is.strings(cliArgs), 'expected list of strings', cliArgs)

  const service = {
    start: 'start',
    url: undefined
  }
  const services = [service]

  let test = 'test'

  if (cliArgs.length === 1 && isUrlOrPort(cliArgs[0])) {
    // passed just single url or port number, for example
    // "start": "http://localhost:8080"
    service.url = normalizeUrl(cliArgs[0])
  } else if (cliArgs.length === 2) {
    if (isUrlOrPort(cliArgs[0])) {
      // passed port and custom test command
      // like ":8080 test-ci"
      service.url = normalizeUrl(cliArgs[0])
      test = cliArgs[1]
    }
    if (isUrlOrPort(cliArgs[1])) {
      // passed start command and url/port
      // like "start-server 8080"
      service.start = cliArgs[0]
      service.url = normalizeUrl(cliArgs[1])
    }
  } else if (cliArgs.length === 5) {
    service.start = cliArgs[0]
    service.url = normalizeUrl(cliArgs[1])

    const secondService = {
      start: cliArgs[2],
      url: normalizeUrl(cliArgs[3])
    }
    services.push(secondService)

    test = cliArgs[4]
  } else {
    la(
      cliArgs.length === 3,
      'expected <NPM script name that starts server> <url or port> <NPM script name that runs tests>\n',
      'example: start-test start 8080 test\n',
      'see https://github.com/bahmutov/start-server-and-test#use\n'
    )
    service.start = cliArgs[0]
    service.url = normalizeUrl(cliArgs[1])
    test = cliArgs[2]
  }

  services.forEach(service => {
    service.start = normalizeCommand(service.start)
  })

  test = normalizeCommand(test)

  return {
    services,
    test
  }
}

function normalizeCommand (command) {
  return UTILS.isPackageScriptName(command) ? `npm run ${command}` : command
}

/**
 * Returns true if the given string is a name of a script in the package.json file
 * in the current working directory
 */
const isPackageScriptName = command => {
  la(is.unemptyString(command), 'expected command name string', command)

  const packageFilename = join(process.cwd(), 'package.json')
  if (!existsSync(packageFilename)) {
    return false
  }
  const packageJson = require(packageFilename)
  if (!packageJson.scripts) {
    return false
  }
  return Boolean(packageJson.scripts[command])
}

const isWaitOnUrl = s => /^https?-(?:get|head|options)/.test(s)

const isUrlOrPort = input => {
  const str = is.string(input) ? input.split('|') : [input]

  return str.every(s => {
    if (is.url(s)) {
      return s
    }
    // wait-on allows specifying HTTP verb to use instead of default HEAD
    // and the format then is like "http-get://domain.com" to use GET
    if (isWaitOnUrl(s)) {
      return s
    }

    if (is.number(s)) {
      return is.port(s)
    }
    if (!is.string(s)) {
      return false
    }
    if (s[0] === ':') {
      const withoutColon = s.substr(1)
      return is.port(parseInt(withoutColon))
    }
    return is.port(parseInt(s))
  })
}

/**
 * Returns the host to ping if the user specified just the port.
 * For a long time, the safest bet was "localhost", but now modern
 * web servers seem to bind to "0.0.0.0", which means
 * the "127.0.0.1" works better
 */
const getHost = () => '127.0.0.1'

const normalizeUrl = input => {
  const str = is.string(input) ? input.split('|') : [input]
  const defaultHost = getHost()

  return str.map(s => {
    if (is.url(s)) {
      return s
    }

    if (is.number(s) && is.port(s)) {
      return `http://${defaultHost}:${s}`
    }

    if (!is.string(s)) {
      return s
    }

    if (
      s.startsWith('localhost') ||
      s.startsWith('127.0.0.1') ||
      s.startsWith('0.0.0.0')
    ) {
      return `http://${s}`
    }

    if (is.port(parseInt(s))) {
      return `http://${defaultHost}:${s}`
    }

    if (s[0] === ':') {
      return `http://${defaultHost}${s}`
    }
    // for anything else, return original argument
    return s
  })
}

function printArguments ({ services, test, namedArguments }) {
  la(
    is.number(namedArguments.expect),
    'expected status code should be a number',
    namedArguments.expect
  )

  services.forEach((service, k) => {
    console.log('%d: starting server using command "%s"', k + 1, service.start)
    console.log(
      'and when url "%s" is responding with HTTP status code %d',
      service.url,
      namedArguments.expect
    )
  })

  if (process.env.WAIT_ON_INTERVAL !== undefined) {
    console.log('WAIT_ON_INTERVAL is set to', process.env.WAIT_ON_INTERVAL)
  }

  if (process.env.WAIT_ON_TIMEOUT !== undefined) {
    console.log('WAIT_ON_TIMEOUT is set to', process.env.WAIT_ON_TIMEOUT)
  }

  console.log('running tests using command "%s"', test)
  console.log('')
}

// placing functions into a common object
// makes them methods for easy stubbing
const UTILS = {
  crossArguments,
  getArguments,
  getNamedArguments,
  isPackageScriptName,
  isUrlOrPort,
  normalizeUrl,
  printArguments
}

module.exports = UTILS